Field of the Invention
The present invention relates to a housing of a centrifugal blower for use in an air conditioner, including a rotatably supported fan wheel, including an inlet opening disposed in an axial direction of the fan wheel and an outlet opening disposed in a radial direction of the fan wheel, a widening diffuser being disposed downstream from the outlet opening in a flow direction, and the fan wheel being disposed in an inner volume of the housing.
Description of the Background Art
Blowers are used in air conditioners to guide fluid flows through the individual elements of the air conditioner. The fluid flows through flow channels, diffusers, heat exchangers and outlet nozzles, among other components.
Acoustic interference noises, which may negatively impair passenger comfort, may arise, in particular, in the area of the blower, which conveys the air flow into the evaporator area of the air conditioner. Centrifugal blowers, which suck in the air in an axial direction and finally blow it out in a radial direction, are regularly used as blowers. To increase the pressure of the air, a diffuser may be connected downstream from the blower in the flow direction.
The interference noises include, in particular, level-determining peaks in the range of 200 Hz to 500 Hz. These peaks are regularly amplified by the special transmission function of an assembly comprising a blower, a diffuser and an evaporator area, whereby the intensity of the noises increases.
A wide range of measures are known in the conventional art, which are aimed at reducing the development of interference noise in or on the blowers for the purpose of producing a preferably high passenger comfort. Foam parts or conductive elements, for example, are known for this purpose, which are mounted on the blower for the purpose of optimizing the air flow. Alternatively, sound dampers are used for the purpose of reducing the developing noises. Helmholtz resonators are also proposed in the literature for the purpose of achieving a reduction in noise.
Perforated plates are proposed in the publications FR 2 780 454 and FR 2 780 348, which are introduced into the air flow at a point downstream from the blower in the flow direction.
The disadvantage of the approaches according to the prior art is, in particular, that significantly higher costs are incurred through the use of the aforementioned measures. Additional pressure losses are also produced, and a reduction in the flow cross section is induced.